Carbide inserted button die



"FIGJ April 18, 1967 -r 3,314,311

CARBIDE INSERTED BUTTON DIE Filed June 22,1964

w/fl, I INVENTOR.

29 RONALD G. BURNET A 30 BY MM,

1 34 www ATIORNEYS United States Patent 3,314,311 CARBIDE INSERTEDBUTTON DIE Ronald G. Burnet, Detroit, Mich., assignor of one-fourth toLloyd Bastian, one-fourth to Walter S. Smith, both of Detroit, Mich.,and one-fourth to Robert Moore,

New Hudson, Mich.

Filed June 22, 1964, Ser. No. 377,005 9 Claims. (Cl. 76-107) Theinvention relates to button dies and refers more specifically to acarbide inserted button die and the method of manufacture thereof.

In the past multiple material dies have been manufactured by producing adie body and an insert separately, after which the insert has beensecured to the die case by brazing or the like with the case and insertaligned as nearly as possible. The die has then been finished by lappingor jig grinding in a separate operation. The separate finishingoperation is necessary since the exact locating of the insert in the diecase on securing the insert to the die case is extremely difficult orimpossible.

This method of producing inserted dies is particularly expensive andinefficient. Further, dies produced by this method are subject topremature failure in use due to misalignment of the insert, stresses setup in the insert during manufacture or shock in use.

It is therefore an object of the present invention to provide animproved method of producing a carbide inserted button die.

Another object is to provide a method of producing a carbide insertedbutton die comprising securing a carbide insert blank in a steel diecase blank and finishing the die opening through the carbide insert anddie case simultaneously by means of electric machining from the rear ofthe die case blank.

Another object is to provide a method of producing a die as set forthabove wherein the carbide insert is secured to the steel die case bymeans of silver solder.

Another object is to provide a method of producing a carbide insertedbutton die wherein a copper cushioning member is positioned between thesteel die case and carbide insert.

Another object is to provide improved button die structure.

Another object is to provide button die structure including a steel diecase and a carbide insert silver soldered to the steel case.

Another object is to provide button die structure as set forth above andfurther including a cushioning member positioned between the carbideinsert and steel die case.

Another object is to provide a carbide inserted button die and method ofmanufacture thereof which is simple, economical and efficient.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawings, illustrating a preferred embodiment of theinvention, wherein:

FIGURE 1 is a diagrammatic elevation view, partly broken away, ofelectric discharge machining apparatus for manufacturing carbideinserted button dies in accordance with the invention.

FIGURE 2 is a longitudinal section view of a carbide inserted button dieconstructed in accordance with the invention.

FIGURE 3 is a cross section of the carbide inserted button dieillustrated in FIGURE 2 taken substantially on the line 3-3 in FIGURE 2.

FIGURE 4 is an enlarged portion of the longitudinal section view of thecarbide inserted button die illustrated 3 ,3 14,3 1 1 Patented Apr. 1 8,1967 ice in FIGURE 2 illustrating in more detail the connection betweenthe carbide insert and steel die case.

With particular reference to the figures of the drawmgs, one embodimentof the invention will now be considered in detail.

As best shown in FIGURE 2 the carbide inserted button die 10 includes asteel case 12 in which a carbide insert 14 has been secured bycushioning structure 16, illustrated best in FIGURE 4.

The carbide inserted button die 10 is manufactured by first producingthe die case 12 and securing a carbide insert 14 thereto with thecushioning means 16 interposed therebetween. The die case 12 and carbideinsert 14 are then electrically machined simultaneously from the rear toprovide a finished button die by electric discharge machining apparatus13 illustrated best in FIGURE 1.

More specifically, the carbide inserted button die 10, as shown inFIGURE 2, includes the case 12 which may be machined of air hardenedtool steel or' which alternatively may be formed from powdered metal byknown processes. Case 12 has the opening 18 extending longitudinallytherethrough which opening includes the slug relief portion 20 and thecarbide insert supporting portion 22 at the opposite ends thereof.

Tear shaped locking recesses 24 are provided around the die case 12 asneeded to lock the button die 10- in a predetermined position in a dieby means of the'usual balls 26. Balls 26 are shown in phantom forillustrative purposes only.

The carbide insert 14 is, as shown, provided with a circular opening 28extending therethrough. It will be understood that the opening 28through the carbide insert 14 and the opening30 in the die case 12 maybe of any desired configuration. Thus, the button die 10 in conjunctionwith a corresponding punch (not shown) may produce square, diamond,star, or irregularly shaped openings in material to be punched.

The cushioning structure 16, as best illustrated in FIG- URE 4, includesa base copper member 32 which may be, for example, three thousandths ofan inch thick, positioned in the bottom 29 of the recess formed byportion 22 of opening 18 and secured to the die case 12 by means ofsilver solder 34. The copper cushioning member 32 is also secured to thecarbide insert 14 by silver solder 34L Cushioning structure 16 furtherincludes the copper cushioning member 36 secured between the axiallyextending walls 38 of the recess formed by the portion 22 of opening 18and the radially outer surface 40 of the carbide insert 14 by the silversolder 34, as shown best in FIGURE 4.

The carbide inserted button die 10 is manufactured by first producingthe die case 12 in blank form of air hardened tool steel or with theusual powdered metallurgy procedures to produce a steel blank having theproperties of air hardened tool steel and subsequently machining the diecase blank to the form illustrated in FIGURE 2. The die case 12 is thenheat treated to a hardness of approximately fifty-eight Rockwell.

A carbide insert blank 14 having a rough undersized opening 28 thereinis then produced separately and secured in the portion 22 of opening 18in die case blank 12 by silver soldering the copper cushioning members32 and 36 as required between the die case 12 and the carbide insertblank 14.

The exterior of the die case is then centerless ground to an exactoutside diameter, after which the insert opening 28 and the centralportion 30 of passage 18 in the die case are electrically machinedsimultaneously from the rear of the die case by electric dischargemachining apparatus 13 to produce a finished carbide inserted buttondie.

Electric discharge machining apparatus, such as apparatus 13 are wellknown in the metal working arts. Apparatus 13 will not therefore beconsidered in detail herein. Briefly however the electric dischargemachining head 15 holding electrode 17 is fed toward button die 10 byservo motor 19 to maintain a predetermined spark gap therebetween inaccordance with the electric potential applied thereacross by thepulsating source of electric energy 21. A dielectric fluid is pumpedthrough electrode 17 and tank 23 by pump 25 during machining.

Thus a carbide inserted button die is produced without the necessity ofexpensive finishing, such as lapping and jig grinding. Further thecarbide inserted button die as disclosed will not be subject to earlyfailure due to cracking of the carbide insert from stresses due todifferential shrinkage of the die case 12 and insert 14 or shock due toimpact in operation.

While one embodiment of the present invention has been disclosed, itwill be understood that other modifications and embodiments arecontemplated. It is the intention to include all such embodiments andmodifications as are defined by the appended claims Within the scope ofthe invention.

- What I claim as my invention is:

1. The method of producing a carbide inserted but-ton die comprisingseparately producing a die case blank and a carbide insert blank,securing the carbide insert blank in the die case blank andsimultaneously electrically machining a die opening completely throughthe carbide insert and die case which opening has the same dimension inthe die case blank and in the carbide insert blank at the inner facebetween the die case blank and carbide insert blank.

2. The method as set forth in claim 1 wherein the opening through thedie case and insert are electrically machined from the rear thereof.

3. The method as set forth in claim 1 and further including securing acushioning member between the carbide insert blank and die case blankprior to said machining.

4. The method of producing a carbide inserted button die comprisingforming a die case blank of air hardened tool steel, machining the blankto a desired form, heat treating the blank, securing a carbide insertblank to the die case blank with cushioning means positionedtherebetween by silver soldering the cushioning means to the die caseblank and to the carbide insert blank, centerless grinding the outsidediameter of the button die to a predetermined exact size andsubsequently simultaneously electrically machining the die openingthrough the die case blank and carbide insert blank.

5. A button die comprising a die case having a die opening extendingaxially therethrough and a recess in one end of the die case over theend of the die opening for receiving a carbide insert, a carbide inserthaving a die opening therein of the same dimension as the die opening inthe die case positioned within the recess in the button die with the dieopenings aligned and means securing the carbide insert within the recessin the die case.

6. The method as set forth in claim 4 wherein the die opening throughthe die case blank and carbide insert blank are electrically machinedfrom the rear thereof.

7. The method of producing a carbide inserted button die comprisingforming a die case blank, machining the blank to a desired form,securing a carbide insert blank to the die case blank with cushioningmeans positioned therebetween by silver soldering the cushioning meansto the die case blank and to the carbide insert blank, centerlessgrinding the outside diameter of the button die to a predetermined exactsize and subsequently simultaneously electrically machining the dieopening through the die case blank and carbide insert blank.

8. The method of producing a carbide inserted button die comprisingforming a die case blank, machining the blank to a desired form,securing a carbide insert blank to the die case blank with cushioningmeans positioned therebetween, centerless grinding the outside diameterof the button die to a predetermined exact size and subsequentlysimultaneously electrically machining the die opening through the diecase blank and carbide insert blank.

9. The method of producing a carbide inserted button die comprisingforming a die case blank, machining the blank to a desired form, forminga carbide insert blank, securing the carbide insert blank to the diecase blank, machining the outside of the button die to a predeterminedexact size and subsequently simultaneously electrically machining thedie opening through the die case blank and carbide insert blank.

References Cited by the Examiner UNITED STATES PATENTS 555,363 2/1896Clark. 2,027,787 1/1936 Ridway et al. 76107 XR 2,121,448 6/1938 Ritzau205-26 XR 2,385,198 9/1945 Engle 205-29 XR GRANVILLE Y. CUSTER, JR.,Primary Examiner.

4. THE METHOD OF PRODUCING A CARBIDE INSERTED BUTTON DIE COMPRISINGFORMING A DIE CASE BLANK OF AIR HARDENED TOOL STEEL, MACHINING THE BLANKTO A DESIRED FORM, HEAT TREATING THE BLANK, SECURING A CARBIDE INSERTBLANK TO THE DIE CASE BLANK WITH CUSHIONING MEANS POSITIONEDTHEREBETWEEN BY SILVER SOLDERING THE CUSHIONING MEANS TO THE DIE CASEBLANK AND TO THE CARBIDE INSERT BLANK, CENTERLESS GRINDING THE OUTSIDEDIAMETER OF THE BUTTON DIE TO A PREDETERMINED EXACT SIZE ANDSUBSEQUENTLY SIMULTANEOUSLY ELECTRICALLY MACHINING THE DIE OPENINGTHROUGH THE DIE CASE BLANK AND CARBIDE INSERT BLANK.